<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    body{
        margin: 0px;
        padding: 0px;
        height: 100vh;
        display: flex;
        justify-content: center;
        align-items: center;
        background: #000;
    }
    .moon{
        position: absolute;
        left: 50%;
        top: 50%;
        width: 300px;
        height: 300px;
        transform: translate(-50%, -50%);
        border-radius: 50%;
        background: #fff;
        box-shadow: 0 0 50px #fff;
    }
    .eclipse{
        position: absolute;
        left: 10px;
        top: 1px;
        width: 300px;
        height: 300px;
        border-radius: 50%;
        background: #000;
        box-shadow: inset 0 0 50px #3a3838;
        transform: rotate(-60deg);
        animation: eclipse 10s infinite linear;
        transform-origin: 50% 150%;
    }
    @keyframes eclipse {
        0%{
            transform: rotate(-60deg);
        }
        90%{
            transform: rotate(30deg);    

        }
        100%{
            transform: rotate(100deg);    

        }
        
    }
</style>
<body>
    <div class="moon">
        <div class="eclipse">

        </div>
    </div>
</body>
</html>